Drier in copier

ABSTRACT

A drier comprises a heater disposed behind a guide plate for drying, a heat reflecting plate for reflecting the heat from the heater toward the guide plate and means for transporting sensitive paper in sliding contact with the guide plate after the paper has been passed through the developing station. The transport means serves to absorb moisture evaporating from the sensitive paper while the paper is moved at a high speed so as to dry the paper rapidly and thoroughly.

UNITED STATES PATENTS 3,177,793 4/1965 Stewart 95/94 R 2,406,494 8/1946 Ferris 34/60 2,207,278 7/1940 Albrecht 34/95 O United States Patent 11 1 1111 3,740,867 Hamaguchi [4 June 26, 1973 1 DRIER IN COPIER 2,328,781 9/1943 Brunk 34/l62 3,074,332 1/1963 Robinson 34/95 X [75] invent: Japan 3,145,637 8/1964 mm 34/162 x 73 1 Assignee; Minolta Camera Kabushiki Kaisha, 3,492,458 1/1970 White et al. 355/10 X Osaka, Japan Primary Examiner-John J. Camby [22] Fled: May 1971 Assistant Examiner-Henry C. Yuen 21 Appli 139 495 Attorney-Stanley Wolder {52] US. Cl. 34/95, 263/6 E, 95/13, [57] ABSTRMFT 355/3 38/11, 219/8 A drier comprises a heater d1sposed behmd a gulde [51] Int. Cl G03g 5/00 Plate for drying a heat reflecting Plate for fleeting 58 Field of Search 34/18, 39, 60, 69, the heat from the heater toward the guide Plate and v 34/95, 151, 355/3, 95/13 38/11 means for transporting sensitive paper in sliding contact with the guide plate after the paper has been [56] References Cited passed through the developing station. The transport means serves to absorb moisture evaporating from the sensitive paper while the paper is moved at a high speed sov as to dry the paper rapidly and thoroughly.

3 Claims, 3 Drawing Figures PAIENIEUJUHZB ma 3.740.867

SHEET 2 [IF 2 Fig. 2

2 32 I O P 19 3136 Invenlor mm; Hanna-ace;

A Home y DRIER IN COPIER BACKGROUND OF THE INVENTION The present invention relates to a drier to be used in a copier of the wet type.

Copiers of the wet type employing an oily or aqueous developer for developing exposed sensitive paper incorporate a drier generally comprising a heater and a guide plate disposed in opposite relationship to the heater, and the sensitive paper is dried while being passed through a path formed between the heater and the guide plate. During such drying operation, the sensitive paper is merely moved through the path without being brought into full contact with guide plate, so that although the guide plate is heated, the heat is not effectively utilized for drying but the paper is dried only with the'radiant heat from the heater. The drying operation conducted in this manner is therefore very inefficient.

On the other hand in recent years, there is a growing tendency to provide copiers which are adapted for copying operation at an increasing speed, but the drying device heretofore known and as described above fails to meet the demand for high speed copying operation.

SUMMARY OF THE INVENTION An object of this invention to provide a drier incorporating therein improved means for heating the guide plate for drying and improved sensitive paper transport means so as to enable the drier to utilize the heat of the heater with the highest efficiency.

Another object of the present invention is to provide a drier which utilizes the heat from the heater with the highest efficiency so as to materially reduce the time required for drying sensitive paper and to thereby eliminate the difficulty which has heretofore bottlenecked a high speed copying operation.

Still another object of this invention is to provide a simplified device which is capable of effecting drying at a substantially improved speed without incorporating a complex structure.

In accordance with the present invention, the guide plate for drying is so arranged as to provide a suitable path for sensitive paper which has been developed and sent out from the developing station, and disposed close to the rear face of the guide plate is a heater for heating the guide plate with conductive heat and intense radiant heat. Positioned further behind the heater is heat reflecting means for reflecting all the radiant heat from the heater toward the guide plate. Thus the heat generated by the heater is substantially concentrated onto the guide plate to heat the same.

Means for transporting the sensitive paper toward an exit in sliding contact with the surface of the guide plate is provided on the guide plate. The transport means comprises an endless belt made of a substantially hygroscopic material such as cotton fabric or the like, which serves to absorb moisture, i.e., steam given out from the sensitive paper when it is subjected to the heat of the guide plate.

Since the heat from the heater is all concentrated onto the guide plate to heat the same and the sensitive paper is moved along the suitably curved guide plate in sliding contact therewith, drying efficiency achieved is very high, with loss of the heat from the heater minimized. Moreover, the sensitive paper transport means absorbs moisture from the paper to promote drying,

with the result that the time required for drying is shortened a great deal as compared with the drying operation by conventional devices. Accordingly, high speed copying operation can be achieved with a substantially simplified device.

Other objects and features of the present invention will become more apparent from the following description of embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in vertical section showing the structural arrangement of a copier of the vertical wet type employing a stationary exposure system, the copier incorporating therein an embodiment of this invention;

FIG. 2 is a view in vertical section showing an embodiment of this invention; and

FIG. 3 is a sectional view showing a modified embodiment of guide plate for drying in accordance with this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, indicated at 1 is an original document; at 2, a document plate made of a transparent plate for placing the document 1 on; and at 3, a document holder made of a flexible elastic sheet such as a rubber sheet.

A pile of sensitive paper 4 is placed in a paper tray 6 in main frame 5 and the paper 4 is sent out from the tray 6 one sheet after another by a paper feed roller 7 to be initiated into operation by an unillustrated start switch or some other operation means. The sensitive paper sent out from the tray 6 is passed along a guide 8, between drive rollers 9, through a passage 10 and into a charging station, where it is charged. The charged paper is then sent to an exposure station 13 by an endless belt 12. When the sensitive paper is brought to a predetermined position in the exposure station 13, the endless belt 12 temporarily comes to a halt, and an exposure lamp 15 in an illuminating section 14 is turned on to illuminate the surface of the document. The reflected light passes through a lens 16 and is reflected by a mirror 17 to strike the sensitive paper to effect exposure, whereby an electrostatic latent image is formed on the surface of the sensitive paper. Upon completion of exposure, the endless belt 12 is initiated into operation again to transport the sensitive paper to a developing station 18, where the latent image is turned into a visible image with a developer containing a toner. The paper is then passed between squeeze rollers 19 into a drier 30 and the dried paper is sent forward between drive rollers 20, through a passage 21, between rollers 22 and is discharged onto a copy tray 24 through an outlet 23.

As shown in FIGS. 1 and 2, the drier 30 comprises a suitably curved guide plate 31 for drying and an endless belt 34 reeved around a drive roller 32 and tension rollers 33 and adapted to move the sensitive paper in sliding contact with the surface of the guide plate 31 when the paper is sent forward by the squeeze rollers 19. The guide plate 31 is provided, in the rear thereof, with a heater 35 and a suitable reflecting plate 36 for reflecting all the heat from the heater 35 toward the guide plate 31. The heater 35 may be disposed in contact with the rear face of the guide plate 31 or alternatively, it may be spaced apart from the guide plate 31 by a small clearance so as to heat the guide plate 31 with intense radiant heat and conductive heat. One or a suitable number of heaters 35 may be provided. The refleeting plate 36 may be curved as illustrated in FIG. 1 or may be in the form of a flat plate as shown in FIG. 2. The form of the reflecting plate 36 may suitably be determined for the best heat reflecting efficiency. The endless belt 34 which is brought into sliding contact with the heated guide plate 31 is made of a cotton fabric or some other hygroscopic material having heat resisting properties so as to take up moisture from the sensitive paper and steam resulting from drying operation to expedite drying of the sensitive paper.

FIG. 3 shows another embodiment of a guide plate to be incorporated in the drier. A guide plate 41 curved with an appropriate curvature is formed in its surface with suitable grooves or indentations 41a to provide a rugged surface so as to reduce the surface areas to be brought into contact with the sensitive paper to such an extent as will not be detrimental to the drying effect achieved by the contact of the paper with the guide plate 41. The structure of the guide plate 41 thus ensures smooth movement of the sensitive paper and serves to eliminate the possible sticking of the paper to the guide plate 41 even when it is slid on the surface of the guide plate in wet state. The guide plate 41, in addition, permits steam to escape through the groove or indentation 41a.

It is also possible to vary the curvature of the guide plate to provide a guide plate having a greater degree of bending which assures a greater area of contact with the sensitive paper in a smaller space for improved drying efficiency. The guide plate may be bent not only in the illustrated form but may also be bent in wavelike form in its entirety. In the case where the guide plate is provided with an indented surface as illustrated in FIG. 3, the projections or indentations may be arranged regularly or irregularly as desired. Alternatively, instead of forming the indentations throughout the entire surface of the guide plate, they may be formed only over a suitably limited area extending from the end thereof at the side of the developing station toward the direction of transport of the sensitive paper and, from the portion of the plate where the moisture of the paper to be in contact therewith is reduced substantially to zero, a curved or flat smooth surface may extend up to the opposite end.

I claim:

1. In a drier to be used in a copier of the wet type for drying sensitive paper while the sensitive paper is passed through a path in the drying station after it has been developed in the developing station, a structure comprising an outwardly curved guide plate for drying, having an outer surface and an inner surface, a heater disposed behind and proximate to said guide plate inner surface and adapted to impart conductive heat and intense radiant heat to said guide plate, a reflecting plate disposed behind and spaced rearwardly from said heater and being shaped and surfaced to reflect substantiallyall the radiant heatincident thereon from said heater toward said guide plate inner surface, and means for transporting the sensitive paper along said outer surface of said guide plate in sliding contact therewith, said transport means including an endless belt having heat resisting and hygroscopic properties for transporting the sensitive paper along the surface of said guide plate in sliding contact therewith and means for driving said endless belt.

2. The drier as set forth in claim 1 wherein said guide plate for drying is curved outwardly with a suitable radius of curvature for effectively receiving the heat produced by said heater directly from said heater and as reflected by said reflecting plate and said transport means is adapted to transport the sensitive paper along the curved surface of said guide plate in sliding contact therewith.

3. The drier as set forth in claim 2 wherein said guide plate for drying is formed with indentations in its surface. 

1. In a drier to be used in a copier of the wet type for drying sensitive paper while the sensitive paper is passed through a path in the drying station after it has been developed in the developing station, a structure comprising an outwardly curved guide plate for drying, having an outer surface and an inner surface, a heater disposed behind and proximate to said guide plate inner surface and adapted to impart conductive heat and intense radiant heat to said guide plate, a reflecting plate disposed behind and spaced rearwardly from said heater and being shaped and surfaced to reflect substantially all the radiant heat incident thereon from said heater toward said guide plate inner surface, and means for transporting the sensitive paper along said outer surface of said guide plate in sliding contact therewith, said transport means including an endless belt having heat resisting and hygroscopic properties for transporting the sensitive paper along the surface of said guide plate in sliding contact therewith and means for driving said endless belt.
 2. The drier as set forth in claim 1 wherein said guide plate for drying is curved outwardly with a suitable radius of curvature for effectively receiving the heat produced by said heater directly from said heater and as reflected by said reflecting plate and said transport means is adapted to transport the sensitive paper along the curved surface of said guide plate in sliding contact therewith.
 3. The drier as set forth in claim 2 wherein said guide plate for drying is formed with indentations in its surface. 